The Southern California locations where Agents of S.H.I.E.L.D. is filmed.

In Episode 18 ("Providence"), Agent Grant Ward breaks Centipede operative Raina out of a
S.H.I.E.L.D. cell, and takes her to a small barber shop in Havana, Cuba, where she
finally meets the mysterious "Clairvoyant" face-to-face.

A true believer, Raina is disappointed to discover that "The Clairvoyant" is actually just a traitorous
S.H.I.E.L.D. agent named John Garrett, who possesses no real psychic gifts, just a very
high-level S.H.I.E.L.D. security clearance that he used to his advantage.

Garrett has her take a seat in a barber chair, which she does reluctantly, and whispers to her:
"Welcome to Hydra," before he pulls a lever which causes her chair to slowly descend
into the floor, down to a secret Hydra headquarters below the barber shop.

This scene was shot in an actual barber shop - but nowhere near Havana.

All they did was hang up a couple of Cuban flags and a few Castro posters.

The same barber shop shows up again in Episode 21 ("Ragtag"),when the agents
find the place, but discover that Hydra has moved out. They go into the empty
Hydra lair, and discover the computer they were looking for.

The small shop is located in a strip mall storefront, in a depressed neighborhood,
about three miles west of the USC campus, tucked away between an
African Methodist Episcopal Church and a Mexican/Salvadorian cafe.